SAN DIEGO — Dinosaur brains may have possessed the capacity for complex vocal communication, a new study hints.

Because brains are soft and break down quickly, dinosaurs left behind few clues about their brainpower. Neuroscientist Erich Jarvis of Duke University and colleagues worked around this problem by studying dinosaurs’ living relatives: birds. The team compared the brains of crocodiles, which evolved before dinosaurs, with the brains of birds, which descended from dinosaurs.